AWS Key Management Service now supports ML-KEM for post-quantum key encapsulation

AWS Key Management Service (KMS) now supports Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM), a post-quantum cryptography standard under [NIST FIPS 203](https://csrc.nist.gov/pubs/fips/203/final), which enables two parties to establish a shared secret. NIST designed ML-KEM to replace the classical key-establishment schemes, like DH/ECDH key agreement, and RSA-based key transport, in their strategic cryptographic roadmap (see [NIST IR 8547](https://csrc.nist.gov/pubs/ir/8547/ipd)). ML-KEM addresses the "harvest now, decrypt later" threat to those classical schemes, where an adversary records the key-establishment exchange today and recovers the shared secret once sufficiently powerful quantum computers become available. KMS supports all three ML-KEM key specs defined in NIST FIPS 203: ML-KEM-512, ML-KEM-768, and ML-KEM-1024\. The Encapsulate API uses the public key to produce a random 32-byte shared secret and its ciphertext form. The Decapsulate API recovers the shared secret from ciphertext using the corresponding private key. KMS protects the private key of an ML-KEM key pair in FIPS 140-3 Level 3 validated hardware security modules (HSMs). You can use the GetPublicKey API to export the public key and distribute it to partners, client applications, or external systems for performing the encapsulate operation locally using cryptographic libraries like AWS-LC, OpenSSL, or Bouncy Castle. ML-KEM is available in all AWS Regions where KMS is available, except the the Middle East (UAE), Middle East (Bahrain), and China Regions. For more information, see [Key spec reference](https://docs.aws.amazon.com/kms/latest/developerguide/symm-asymm-choose-key-spec.html) in the AWS KMS Developer Guide.